Hi all, I post some focault pictures where we can se what happens to the glass when we touch our hands on the mirror edge. On that case I touched the glass for...
Is this plate glass or low expansion glass? Yes I used gloves on my 16 x 1 inch plate mirror figured by hand. You also need 4 or 5 hours to let plate glass...
I looked at the 10 f5 60 year old uncoated Pyrex mirror under different lighting conditions last night when I took it back to the makers shop. I could see what...
... I was told that it´s pirex, some guys from the local observatory made a cleanup on their storage room and gave it to me. The glass shows an yellowish...
I tried what is for me a new way to star test and then compared it to my simulated star test from interferometry data. The mirror is an 8 inch with ROC of 119...
Dale, If they're striations in the glass itself they can/will affect the polishing/figuring on the surface - I've seen this with small localized strain spots...
I seem to remember reading that the way to protect a polished surface on a lens (in this case a schmidt corrector) while working on the second surface was to...
George, That sounds like it would work - note there is a product whose name escapes me designed especially for providing a protective coating for optics. It's...
Hi Mark I believe that you are talking about a colloidon (sp) that a lot of people use for cleaning mirrors. We have used it at work for cleaning some first...
curious IDEAL If I used a standard mirror ,a home mirror whit back paint on; this back surface is probaly better then a standard glass is it polish;and if so...
Jack, Regular vanity mirrors are not special glass and are not that flat. You can often see the surface variations by looking at the reflection and moving your...
Hello everyone, My question is simply what formulas you all use for calculating (Y) and (X) for caustic testing using a moving source light. This should be ...
... racked ... when you ... the top of ... spare ... dimentions ... Hello , Arjan and Ken , I was searching for this info and found this 3 month old post,...
Brent, Look here: http://home.earthlink.net/~burrjaw/atm/atm_math.lwp/atm_math.htm Most people will agree with Jim and his collaborators. :) The formula you...
... They sure do, several kinds, of which Borofloat seems the best. Word I heard is that they're about to start providing thick sheet glass as well, but I...
... that's good to know, cause one of the customer I deal with was told by a major distributor here in Los Angeles that they were not going to carry 3/4" plate...
Good News: I have finished grinding and polishing the face of the corrector. With a 100LPI ronchi set just outside of focus (with a backlight) the lines are...
The list is slow so here's a question (or two): What experience have people had regarding the workability of glass with different anneals? I'm not talking...
That depends on your experience an skill level. Almost nothing is too thin however the dificulity of creating a good figure goes up as they get thinner. More...
... There's no sharp demarcation between thick-enough and too-thin. Instead it's a gradual shading of increasing complexity and new techniques. My rule of...
This interesting item: http://tinyurl.com/2v82n8 for a 20" blank molding process, from the embeddedRF people, who've occasionally marketed (or at least hinted)...
... Might be tricky but sounds doable based on what Ive seen other do on the net. I recall more than one 16" out of 3/4" glass but your getting to the upper...
New to this group, first mirror and need a little advice if someone could spare a minute ... It appears that I am now quite close to a sphere, with the...
